Palm gets a new CEO

Palm (PALM) CEO Ed Colligan is leaving and will be replaced by executive chairman Jon Rubinstein. Rubinstein, formerly of Apple (AAPL), is credited with being the primary force behind the new Pre.

Why did Colligan "decide" to leave after 16 years at the company? There are several theories, but no one outside Palm may ever know. The theory that should worry investors the most is that sales of the Pre are off to a worse start than Palm's board expected.